As mentioned before, East Passyunk’s Plenty has been undergoing changes — some small, some big — since Anthony Mascieri took ownership of the quickserve, coffee bar and prepared foods operation over the summer, but with renovations complete, and menus tweaked, the shop’s ready for its closeup. Tonight, Mascieri’s hosting a grand re-opening celebration from 5 to 9 p.m., serving some of the new menu items, and offering complimentary refreshments. That new menu goes live tomorrow, and this coming weekend brunch service makes its big debut.